The present invention relates to a group of aza-benzothiopyranoindazole compounds having antitumor activity, and processes for their preparation.
Cellular Proliferation and Cancer.
The disruption of external or internal regulation of cellular growth can lead to uncontrolled proliferation and in cancer, tumor formation. This loss of control can occur at many levels and, indeed, does occur at multiple levels in most tumors. Further, although tumor cells can no longer control their own proliferation, they still must use the same basic cellular machinery employed by normal cells to drive their growth and replication.
Aza-Benzothiopyranoindazoles Antitumor Agents.
Certain 1,4-bis[(aminoalkyl)amino]anthracene-9,10-diones have been reported which show antitumor activity in clinical trials. Of particular interest has been ametantrone, 1,4-bis[(2-(2-hydroxyethylamino)ethyl)amino]anthracene-9,10-dione and mitoxantrone, 5,8-dihydroxy-1,4-bis[(2-(2-hydroxyethylamino)ethyl)amino]anthracene-9,10-dione (Zee-Cheng et al., xe2x80x9cAntineoplastic Agents. Structure-Activity Relationship Study of Bis(substituted aminoalkylamino)anthraquinones,xe2x80x9d J. Med. Chem. 21:291-294 (1978); and Cheng et al., xe2x80x9cProgress in Medicinal Chemistryxe2x80x9d, Ellis, G. P. and West, G. B., Elsevier: Amsterdam, vol. 202, p. 83 (1983)).
Mitoxantrone is a broad-spectrum oncolytic agent, whose activity is similar to that of the anthracyclines antibiotic doxorubicin. Clinical trials have demonstrated a diminish cardiotoxicity in comparison to doxorubicin. Both mitoxantrone and ametantrone have remarkable myelodepressive toxicity and both compounds show cross-resistance to cell histotypes developing resistance against doxorubicin mediated by overexpression of glycoprotein P (also known as multidrug resistance).
In an attempt to overcome the above-mentioned drawbacks, some chromophore modified anthracendiones have been reported.
Blanz et al., J. Med. Chem. 6:185-191 (1963) discloses the synthesis of a series of thioxanthenones related to lucanthones and the results of the testing of the compounds against leukemia and two solid tumors. Among the compounds disclosed are: 
where R is methyl, methoxyl, and ethoxyl.
Yarinsky et al., J. Trop. Med. and Hyg. 73:23-27 (1970) discloses 
as an antischistosomal agent.
Palmer et al., xe2x80x9cPotential Antitumor Agents. 54. Chromophore Requirements for in vivo Antitumor Activity Among the General Class of Linear Tricyclic Carboxamides,xe2x80x9d J. Med. Chem. 31(4):707-712 (1988) discloses N-[2-(dimethylamino)ethyl-]-9-oxo-9H-thioxanthene-4-carboxamide monohydrochloride which was tested in vitro versus murine leukemia (L1210) and in vivo versus P388 leukemia cells and was found to be xe2x80x9cunlikely to worth pursuingxe2x80x9d as a potential antitumor agent.
U.S. Pat. No. 4,539,412 to Archer discloses compounds of the formula: 
where for Xxe2x95x90S: R1 and R2 are individually selected from one of lower-alkyls, and jointly selected from one of pyrolidinyl, piperidinyl, morpholinyl, piperazinyl and N-substituted piperazinyl; and R3 is hydroxy. The compounds are said to be useful as antitumor agents.
However, the search for newer active analogues is still highly desirable. WO 94/06795 describes aza-thiopyranopyridine derivatives which are endowed with antitumor activity. WO 98/49172 to Krapcho discloses compounds of the formula: 
where one of X, Y, or T is nitrogen (xe2x95x90Nxe2x80x94) and the others are xe2x95x90CHxe2x80x94; D is selected from the group consisting of C1-C4 alkyl, nitro or xe2x80x94NHxe2x80x94A, where A is on its turn is selected from the group consisting of hydrogen, xe2x80x94COxe2x80x94, CH2xe2x80x94NR2R3 and alkyl. B is selected in the group consisting of C1-C10 alkyl having one or two substituents selected from the group consisting of OR1 and xe2x80x94NR2R3. These compounds have antitumor activity against human leukemias and solid tumors sensitive to treatment with mitoxantrone and antitumor antibiotics, such as doxorubicin.
Aza-derivatives of lucanthone have also been described. For example, M. Croisy-Delcey et al., xe2x80x9cAza Analogues of Lucanthone: Synthesis and Antitumor and Bactericidal Properties,xe2x80x9d J. Med. Chem. 26(9):1329-1333 (1983) and Blanz et al., J. Med. Chem. 6:185-191 (1963) describe the following compounds, respectively: 
where R is an aminoalkyl chain and, in (2), one of X or Y is nitrogen and the other is carbon. In both the cases these compounds showed little, if any, antitumor activity.
U.S. Pat. No. 5,346,917 to Miller et al. discloses compounds of the formula: 
where n is 2 or 3; R is hydrogen, C(O)H, C(O)R3, SO2R3 and C(O)OR3; R1 and R2 are independently hydrogen or lower alkyl; and R9 is hydrogen, lower-alkyl; lower-alkoxy, or hydroxy.
In addition, European Patent Application No. 127,389 to Elslager et al. discloses N,N, diethyl-5-methyl-2H-[1]-benzothiopyrano[4,3,2-cd]indazole-2-ethanamine which is stated to be useful as an antitumor agent.
European Patent Application No. 284,966 to Beylin et al. discloses a process for preparing compounds of the formula: 
where X is oxygen, sulfur or selenium; D and Dxe2x80x2 may be the same or different and are a straight or branched alkylene group of from two to five carbon atoms; R1 and R2 may be the same or different and are hydrogen or an alkyl group of from two to eight carbon atoms which may be substituted by hydroxy; R3, R4, R5 and R6 may be the same or different and are hydrogen or hydroxy; or a pharmaceutically acceptable salt thereof. The compounds are stated to possess antibacterial, antifungal and antineoplastic activity. A similar disclosure is found in Beylin et al., J. Heterocyclic Chem. 28:517-527 (1991).
U.S. Pat. No. 3,505,341 to Elslager et al. discloses compounds of the formula: 
where A is an alkylene radical containing 2 to 4 carbon atoms; Q is a hydrogen or halogen atom; R1 and R2 are the same or different and represent C1-C4 alkyl or together with the nitrogen atom [xe2x80x94N(R1)R2] a lower alkylene radical containing 4 to 8 carbon atoms, 4 to 6 of which are joined in a ring with the nitrogen atom; and W is the aldehyde group xe2x80x94CHO or a methyl or hydroxymethyl group. The compounds are stated to possess antiparasitic and antibacterial activity.
U.S. Pat. No. 3,963,740 to Elslager discloses compounds of the formula: 
where A is an alkylene radical containing 2 to 4 carbon atoms. R1 and R2 are the same or different and represent C1-C4 alkyl or together a lower-alkylene radical containing 4 to 8 carbon atoms, 4 to 6 of which are joined in ring with the nitrogen atom; and W is methyl, hydroxymethyl, or acyloxymethyl where said acyl fragment contains from one to eight carbon atoms; Y is S or O; and one of Q and R is hydrogen and the other is selected from hydrogen and a substituted halo or alkoxy group having one to four carbon atoms. The compounds are stated to be intermediates in the preparation of the corresponding N-oxide derivative which are stated to be useful as parasiticidal agents. A similar disclosure is found in U.S. Pat. No. 4,026,899 to Elslager.
Blanz et al., J. Med. Chem. 6:185-191 (1963) discloses 5-methyl-2H-[1]benzothiopyrano[4,3,2-cd]indazole (example 39) which was tested and found to be inactive as an antitumor agent.
Showalter et al., xe2x80x9cBenzothiopyranoindazoles, A New Class of Chromophore Modified Anthracenedione Anticancer Agents. Synthesis and Activity Against Murine Leukemias,xe2x80x9d J. Med. Chem. 31(8):1527-1538 (1988) discloses the synthesis and anticancer activity of a series of substituted 5-amino-2H-[1]benzothiopyrano[4,3,2-cd]indazol2-2-ethanamine.
Baily et al., Biochem. 32:5985-5993 (1993) discloses compounds of the formula: 
where R1xe2x95x90Cl and R2xe2x95x90CH3; R1xe2x95x90Cl and R2xe2x95x90CH2OH. The compounds are stated to exhibit antitumor activity.
Gordon et al., xe2x80x9cAntimuscarinic Activities of Hycanthone Analogs: Possible Relationship with Animal Toxicity,xe2x80x9d J. Pharm. and Exp. Ther. 236(1):85-89 (1986) discloses N,N-diethyl-5-methyl-8-chloro-2H-[1]benzothiopyrano-[4,3,2-cd] indazole-2-ethanamine and their testing for antimuscarinic activity.
WO 94/06795 describes aza-benzothiopyranoindazole derivatives which are endowed with antitumor activity. U.S. Pat. No. 5,935,969 to Krapcho discloses compounds of the formula: 
where one of X, Y, Z, or T is nitrogen (xe2x95x90Nxe2x80x94) and the others are xe2x95x90CHxe2x80x94; D is selected from the group consisting of nitro or xe2x80x94NHxe2x80x94A, where A is on its turn is selected from the group consisting of hydrogen, xe2x80x94COxe2x80x94, CH2xe2x80x94NR2R3 or alkyl. B is selected in the group consisting of C1-C10 alkyl having one or two substituents selected from the group consisting of OR, and xe2x80x94NR2R3.
U.S. Pat. No. 5,532,263 to Wentland et al. discloses compounds of the formula: 
where n is 2 or 3; R is hydrogen, C(O)H, C(O)R3, SO2R3 and C(O)OR3; R1 and R2 are independently hydrogen or lower alkyl; and R9 is hydrogen, lower-alkyl; lower-alkoxy, or hydroxy.
The present invention is directed to overcoming these deficiencies in the art.
The present invention is directed to a compound of the following formula: 
where:
W is selected from the group consisting of S, SO, and SO2;
Q is a 5- or 6-membered aromatic ring having at least one atom selected from the group consisting of N and S;
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H; C(O)OR1; SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected in the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom or
pharmaceutically acceptable salts.
Another aspect of the present invention is directed to a process for preparation of a product compound of the formula: 
where:
one or more of X, Y, Z, or Txe2x95x90N;
W is selected from the group consisting of S, SO, and SO2;
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H, C(O)OR1, SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10 alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom; or
pharmaceutically acceptable salts thereof, said process comprising:
transforming a first intermediate compound of the formula: 
under conditions effective to form the product compound.
The present invention is also directed to a process for preparation of a product compound of the formula: 
where:
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H; C(O)OR1; SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected in the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10 alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom; or
a pharmaceutically acceptable salt thereof, said process comprising:
transforming a first intermediate compound of the formula: 
wherein Uxe2x80x2=H, F, Cl, Br or I, under conditions effective to form the product compound.
The present invention is also directed to a process for preparation of a product compound of the formula: 
where:
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H; C(O)OR1; SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected in the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10 alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3;
E is OCH3 or Cl; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom; or
a pharmaceutically acceptable salt thereof, said process comprising:
transforming a first intermediate compound of the formula: 
xe2x80x83under conditions effective to form the product compound.
The present invention is also directed to a method for inhibiting cell proliferation in mammals. This method involves administering to a mammal a therapeutically effective amount of the compound of the following formula, and as described above: 
The present invention is also directed to a pharmaceutical composition of matter including the following compound and one or more pharmaceutical excipients: 
The present invention is directed to a compound of the following formula (I): 
where:
W is selected from the group consisting of S, SO, and SO2;
Q is a 5- or 6-membered aromatic ring having at least one atom selected from the group consisting of N and S;
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H; C(O)OR1; SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected in the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10 alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom or
pharmaceutically acceptable salts.
A preferred form of the compound of the present invention has the following formula (II): 
where:
one or more of X, Y, Z, or Txe2x95x90N;
W is selected from the group consisting of S, SO, and SO2;
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H, C(O)OR1, SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10 alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom; or
pharmaceutically acceptable salts thereof.
Examples of the class of compounds according to formula (II) are set forth in Table 1.
Examples of preferred compounds of formula (II) are described in Table 2, below.
Synthetic Schemes for Preparation of the Compounds of Formula (II)
The compounds of formula (II) can be prepared by a number of synthetic schemes.
One example of such a scheme is that of Scheme 1 as follows: 
Cyclization of compound 1, where X, Y, Z, and T are as above defined and where U is Cl, can be accomplished with concentrated sulfuric acid at 130xc2x0 C. to give a mixture of isomers compounds 2 and 3. Next, condensation of the mixture of compounds 2 and 3 with NH2NHB at 165xc2x0 C. can yield the desired product 4, which can be separated from the byproduct 5 by column chromatography. Reaction of compound 4 with CHCl2OCH3 and AlCl3 can yield the desired aldehyde 6. The resulting intermediate can be reacted with formic acid and formamide (Leuckart Conditions) to provide the formamide intermediate. The latter compound can be hydrolyzed with 2 N NaOH to give the desired amine 7. Compound 7 can be converted to compounds of formula II using chemical transformations known to those skilled in the art.
Alternatively, compounds 2 and 3 can be prepared by cyclization of the compound 1 in which X, Y, Z, and T are as above defined and U is selected from the group consisting of F and Cl. This reaction can be performed using different methods known in the art, such as:
(i) Transforming the carboxylic acid moiety into an acyl chloride by reaction with thionyl chloride, for example, and, subsequently, performing a Friedel-Crafts reaction in the presence of a Lewis acid, such as aluminum trichloride, in a suitable solvent, such as nitrobenzene and at a temperature ranging from between 0xc2x0 C. and 150xc2x0 C.; and
(ii) Cyclizing the compounds (3) in the presence of concentrated sulfuric acid at a temperature ranging from room temperature to 150xc2x0 C.
Compounds of formula 4 and 5 can alternatively be prepared from the reaction of a mixture of compounds 2 and 3 with substituted hydrazine: H2Nxe2x80x94NHxe2x80x94Bxe2x80x2, where Bxe2x80x2 is the same as B as defined in formula (II) above, or Bxe2x80x2 is a group that can be converted into B by removal of protective groups for the primary or secondary amines and hydroxy groups optionally present in Bxe2x80x2, to give compound 4. The reaction of compounds 2 and 3 with the substituted hydrazine can be done by reacting the mixture with at least a stoichiometric amount of the substituted hydrazine. The reaction is usually performed in an inert solvent such as methylene chloride, chloroform, 1,1,1-trichloroethane, dimethoxyethane, tetrahydrofuran, dimethylsulfoxide, dimethylformamide, pyridines and mixtures thereof, or if it is desired using the substituted hydrazine itself as the solvent.
As shown in Scheme 2, when X is nitrogen, compound 10 can be obtained by reacting 2-chloro-nicotinic acid (8) with 2,5-disubstituted thiophenol (9) in refluxing acetone as follows: 
When Y is nitrogen, compound 12 can be obtained by reacting the dizonium salt of 3-amino-4-carboxylic acid pyridine (11) with the anion of 2,5-disubsituted thiophenol (9) in refluxing acetone as outlined in Scheme 3 below: 
When Z is nitrogen, compound 14 can be obtained by reacting 4-chloronicotinic acid (13) and 2,5-disubstituted thiophenol (9) in a solvent at temperatures from room temperature up to the boiling point of the solvent. A preferred condition is to reflux the mixture of the two reactants in acetone as a solvent. This process for producing compound 14 may be carried out as depicted in Scheme 4 below: 
When T is nitrogen, compound 16 can be obtained by reacting the diazonium salt of 3-amino-2-carboxylic acid pyridine (15) with the anion of 2,5-disubstituted thiophenol (9) in refluxing acetone as depicted in Scheme 5 below: 
An alternative regioselective synthesis for compound 4 (where Xxe2x95x90N or Zxe2x95x90N) is detailed in Scheme 6 below: 
As depicted in Scheme 6, 2-fluoro-5-bromothiophenol (9) is reacted with 4-chloro-3-carboxylic acid pyridine (17) (Xxe2x95x90CH, Zxe2x95x90N) in refluxing acetone to yield compound 18 (Xxe2x95x90CH, Zxe2x95x90N). Compound 18 is then converted to the acetyl chloride derivative which cyclized upon treatment with aluminium chloride to give compound 19 (Xxe2x95x90CH, Zxe2x95x90N). Upon condensation of compound 19 with the appropriate substituted hydrazine in DMF at 70xc2x0 C., the tetracyclic core 20 (Xxe2x95x90CH, Zxe2x95x90N) is isolated. Compound 20 (Xxe2x95x90CH, Zxe2x95x90N, Uxe2x80x2xe2x95x90Cl or Vxe2x95x90Br) is converted to compound 4 (Xxe2x95x90CH, Zxe2x95x90N) via either two routes. In the first route, compound 20 is reacted with alkyl lithium, followed with quenching the reaction with dimethylformamide at xe2x88x9278xc2x0 C. to give the desired product 4 (Xxe2x95x90CH, Zxe2x95x90N). In the second route, compound 20 (Xxe2x95x90CH, Zxe2x95x90N, Uxe2x80x2xe2x95x90Cl or Br) is treated with Pd (O) and the appropriate ligand (21 or 22, which can be prepared according to Arduengo III et al., Tetrahedron 55:14523-14534 (1999), which is hereby incorporated by reference in its entirety) to give compound 4 (Xxe2x95x90CH, Zxe2x95x90N). Alternatively, when Uxe2x80x2xe2x95x90Br, compound 4 (Xxe2x95x90CH, Zxe2x95x90N) can be obtained by reductive debromination of compound 20 using Pd/C and H2(g). Using a similar approach, the aza series where Xxe2x95x90N, Zxe2x95x90CH can be constructed from 2-chloro-3-carboxylic acid pyridine (17) (Xxe2x95x90N, Zxe2x95x90CH) (Scheme 6, above).
An alternative regioselective synthesis for compound 4 (where Yxe2x95x90N or Txe2x95x90N) is depicted in Scheme 7 below. 
As for the aza series (Scheme 7) where Yxe2x95x90N, Txe2x95x90CH or Yxe2x95x90CH, Txe2x95x90N, the corresponding compound 4 (Yxe2x95x90N, or Txe2x95x90N) can be derived from multisteps synthesis starting from the corresponding amines (23) where Yxe2x95x90N, Txe2x95x90CH or Yxe2x95x90CH, Txe2x95x90N, respectively, using a sequence of synthetic steps described above, and as described in Scheme 7, above.
As depicted in Scheme 8 (below), compound 9 (Uxe2x95x90F, Uxe2x80x2xe2x95x90Br) can be synthesized in three steps from commercially available material, including, for example, from 2-bromo-5-fluoro-phenol (27). Hence, reaction of compound 27 with N-N-dimethylthiocarbamoyl chloride in the presence of NaH in DMF, yields compound 28. Heating compound 28 in diphenyl ether at 260xc2x0 C. results in Newmann-Kwart rearrangement to give compound 29. Upon reaction with potassium hydroxide in methanol followed by an acidic workup, compound 29 yields the desired compound 9. 
Synthesis of a specific 2-Aza acid intermediate (11) used in Scheme 3 of the present invention is shown below as Scheme 9: 
As depicted in Scheme 9, above, the commercially available pyridine-3,4-dicarboxylic acid (30) can be treated with acetic anhydride to give cinchonomeric anhydride (31). Upon treatment of anhydride 31 with acetamide, the aza-imide 32 can be obtained. The aza-imide 32 can be converted to 3-aminoisonicotinic acid (11) by treatment with sodium hypobromite.
Synthesis of a specific 3-Aza acid intermediate (13) used in Scheme 4 of the present invention is shown below as Scheme 10: 
As depicted in Scheme 10 (above), 4-chloronicotinic acid (13) can be derived from direct metallation of the commercially 4-chloropyridine (33). Alternatively, compound 13 can be derived through a sequence of steps from 3-picoline-N-oxide (34). Therefore, compound 34 can be nitrated with nitric acid and sulfuric acid to give product 35. The deoxygenation of N-oxide and displacement of the nitro group by phosphorous trichloride can lead to compound 36. Treatment of 36 with hot aqueous potassium permanganate can lead to 4-chloronicotinic acid (13).
Synthesis of the 4-Aza acid intermediate 15 used in Scheme 5 of the present invention is shown below as Scheme 11: 
As described above in Scheme 11, compound 15 can be prepared in three steps from commercially available pyridine-2,3-dicarboxylic acid (37). Specifically, compound 37 can be converted to the oxo-imide 38 upon treatment with acetic anhydride. Upon treatment of compound 38 with acetamide, the desired aza-imide 39 can be obtained. Aza-imide 39 can be converted to the desired amino pyridine 15 upon treatment with sodium hypobromite.
An example of oxidation of the sulfur of the aza-benzothiopyranoindazoles analogues described in Scheme 1 of the present invention is shown below as Scheme 12: 
As shown in Scheme 12, compounds of formula (11), when reacted with NaIO4, MeOH, and H2O, can be converted to compound 40, where n is the integer 1. Moreover, compounds of formula (II) can be reacted with oxone, MeOH, and buffer (at pH 11-12) to yield compound 40, where n is the integer 2.
Another synthetic scheme for preparing compounds of formula (II) of the present invention is shown below in Scheme 13: 
As depicted above in Scheme 13, 4-chloro-quinolinone (42) can be derived from quinolin-4-ol (41) using phosphorous oxycloride. Upon oxidation of compound 42 with potassium permanganate, compound 43 can be obtained. Reaction of compound 43 with acetic anhydride can yield the oxo-imide derivative 44. Compound 44 can be converted to the aza-imide upon reaction with acetamide, which is hydrolyzed to the desired amino pyridine derivative 45 upon treatment with sodium hypobromite. Diazotization of compound 45 under aqueous conditions will give the corresponding phenol derivative 46. Reaction of compound 46 with methyl iodide and potassium carbonate will yield the desired methyl ether pyridine derivative 47. Analog 47 can be further elaborated in several steps to yield compound 48 using synthetic strategies described in the present application or synthetic methodologies known by those skilled in the art. Moreover, upon reaction of analog 47 with phosphorous oxychloride, the desired 2,4-dichloro substituted pyridine derivative 49 can be obtained. Compound 49 can be converted in several steps to the desired target 50 using synthetic strategies described in the present application or using methodologies known to those skilled in the art.
Another synthetic scheme for preparing compounds of formula (II) is shown below in Scheme 14: 
As shown above in Scheme 14, compound 53 can be prepared by reacting pyridazine-4-carboxylic acid ethyl ester (51) with 2,6-dichlorobenzaldehyde (52) in the presence of FeSO4xe2x80x94(CH3)3CO2H. Ketone 53 can be converted to compound 54 upon reaction with thionyl chloride. Upon treatment of compound 54 with sodium azide, ketone 55 can be obtained. Compound 55 can be subjected to Hoffmann rearrangement conditions to give amine 56. Treatment of compound 56 with methyl iodide or benzyl iodide results in the formation of the iminium salt 57. Hydrolysis of compound 57 could lead to the formation of ketone 58. Dealkylation of 58 could afford 59. Reaction of compound 59 with phosphorous pentasulfide in refluxing pyridine yields the 2,3-diazathioxanthenone system 60. Compound 60 can be elaborated in several steps to yield the desired compound 61 using synthetic strategies described in the present application or using synthetic methodologies known to those skilled in the art.
Another preferred form of the compound of the present invention has the following formula (III): 
where:
X, Y, or Zxe2x95x90S;
A is selected from the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; C(O)H; C(O)OR1; SO2R1; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
B is selected in the group consisting of: hydrogen; C1-C4 linear, branched, or cyclic alkyl which is substituted or unsubstituted; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; hydroxy; (CH2)nNH(CH2)mCH3; (CH2)nN((CH2)mCH3)(CH2)pCH3; and (CH2)nD;
R1 is selected from a group consisting of C1-C10 alkyl, phenyl, and phenyl alkyl, as free bases;
n is 2-3;
m is 0-3;
p is 0-3; and
D is selected from the group consisting of: hydroxy; C1-C4 linear or branched alkoxy which is substituted or unsubstituted; and a 5- or 6-member aromatic or non-aromatic heterocyclic ring containing a sulfur, oxygen, or nitrogen heteroatom, or
a pharmaceutically acceptable salt thereof.
Another preferred form of the compound of the present invention has the following formula (III): 
where A and B are as described above, or
a pharmaceutically acceptable salt thereof.
Another preferred form of the compound of the present invention has the following formula (III): 
where A and B are as described above, or
a pharmaceutically acceptable salt thereof.
Another preferred form of the compound of the present invention has the following formula (III): 
where A and B are as described above, or
a pharmaceutically acceptable salt thereof.
Examples of the class of compounds according to this formula (III) are set forth in Table 3.
Synthesis of the thiophene derivatives of formula (III) of the present invention is shown below as Scheme 15. 
As described in Scheme 15, compound 63 can be prepared from bromination reaction of commercially available thiophene-3-carbaldehyde (62) which is first protected as diacetal. Compound 63 can be further oxidized to the carboxylic acid derivative 64 using silver oxide. Coupling of 64 with the appropriate 2,5-disubstituted thiophenol followed by cyclization yields the tricyclic system 65. Compound 65 can be further elaborated to yield compound 66 using synthetic steps described in the present application or using synthetic methodologies known to those skilled in the art.
The present invention is also directed to a method for inhibiting cell proliferation in mammals. This method involves administering to a mammal a therapeutically effective amount of the compound of the following formula, and as described above: 
The present invention is also directed to a pharmaceutical composition of matter including the following compound and one or more pharmaceutical excipients: 
Based on the results obtained in the standard pharmacological test procedures described below, the compounds of the present invention are useful as antineoplastic agents. More particularly, the compounds of the present invention are useful for inhibiting the growth of neoplastic cells, causing cell death of neoplastic cells, and eradicating neoplastic cells. The compounds of the present invention are, therefore, useful for treating solid tumors, including sarcomas and carcinomas, such as astrocytomas, prostate cancer, breast cancer, small cell lung cancer, and ovarian cancer, leukemias, lymphomas, adult T-cell leukemia/lymphoma, and other neoplastic disease states.
The compounds of the present invention can be administered orally, parenterally, for example, subcutaneously, intravenously, intramuscularly, intraperitoneally, by intranasal instillation, or by application to mucous membranes, such as, that of the nose, throat, and bronchial tubes. They may be administered alone or with suitable pharmaceutical carriers, and can be in solid or liquid form such as, tablets, capsules, powders, solutions, suspensions, or emulsions.
The active compounds of the present invention may be orally administered, for example, with an inert diluent, or with an assimilable edible carrier, or they may be enclosed in hard or soft shell capsules, or they may be compressed into tablets, or they may be incorporated directly with the food of the diet. For oral therapeutic administration, these active compounds may be incorporated with excipients and used in the form of tablets, capsules, elixirs, suspensions, syrups, and the like. Such compositions and preparations should contain at least 0.1% of active compound. The percentage of the compound in these compositions may, of course, be varied and may conveniently be between about 2% to about 60% of the weight of the unit. The amount of active compound in such therapeutically useful compositions is such that a suitable dosage will be obtained. Preferred compositions according to the present invention are prepared so that an oral dosage unit contains between about 1 and 250 mg of active compound.
The tablets, capsules, and the like may also contain a binder such as gum tragacanth, acacia, corn starch, or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, lactose, or saccharin. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a fatty oil.
Various other materials may be present as coatings or to modify the physical form of the dosage unit. For instance, tablets may be coated with shellac, sugar, or both. A syrup may contain, in addition to active ingredient, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye, and flavoring such as cherry or orange flavor.
These active compounds may also be administered parenterally. Solutions or suspensions of these active compounds can be prepared in water suitably mixed with a surfactant, such as hydroxypropylcellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof in oils. Illustrative oils are those of petroleum, animal, vegetable, or synthetic origin, for example, peanut oil, soybean oil, or mineral oil. In general, water, saline, aqueous dextrose and related sugar solution, and glycols such as, propylene glycolor polyethylene glycol, are preferred liquid carriers, particularly for injectable solutions. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.
The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms, such as bacteria and fungi. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g., glycerol, propylene glycol, and liquid polyethylene glycol), suitable mixtures thereof, and vegetable oils.
The compounds of the present invention may also be administered directly to the airways in the form of an aerosol. For use as aerosols, the compounds of the present invention in solution or suspension may be packaged in a pressurized aerosol container together with suitable propellants, for example, hydrocarbon propellants like propane, butane, or isobutane with conventional adjuvants. The materials of the present invention also may be administered in a non-pressurized form such as in a nebulizer or atomizer.